Zinc nitride (Zn3N2) films were prepared by radio-frequency magnetron sputtering from a pure Zn target in a N-2 ambient. Films were deposited on glass and Si(100) substrates at 298- and 473-K substrate temperatures (T-s). Ion beamanalysis (IBA) techniques, spectroscopic ellipsometry (SE) and transmission spectroscopy were used to characterize the samples as a function of T-s and time. IBA studies showed that the Zn and N concentrations matched the stoichiometric values 3:2 of the cubic anti-bixbyte structure and revealed the partial transformation of Zn3N2 into zinc oxide (ZnO) due to the exposure to ambient air. IBA and SE techniques revealed films grown at higher T-s were less affected by the oxidation process. Transmission spectroscopy showed that the band gap energy blue shifted as T-s decreased. It was also found that the oxidation process produced a blue shift of the band gap energy. For the sake of comparison, ZnO/Zn3N2 heterostructures were synthesized using the same system and characterized in parallel to unintentionally oxidized nitride layers. SE studies of the heterostructure showed that the deposition of a ZnO layer helped to prevent nitride oxidation. (C) 2012 Elsevier B. V. All rights reserved.